Capillary-sized parallel plate supercapacitors for in-operando study of voltage driven MXene electrode degradation.

This project is aimed on in operando experiments with Ti3C2Tx Mxene based capillary- size supercapacitors using XRD under conditions of charge-discharge cycling. XRD will be used for characterization of electrode microstructure evolution under conditions of supercapacitor operation in several types of electrolytes (H2SO4 and alkali metal salts) with progressively large size of ions (LiCl, NaCl, KCl, KI). Evolution of Mxene structure will be studied by following effects of swelling, intercalation and de-intercalation of ions as a function of applied voltage, change of charging polarity and repeated cycling. Degradation of Mxene in a set of electrolytes will be studied using stepwise increase in applied voltage from 0.5V up to 1.1V to reveal limits and mechanism of Mxene electrode degradation. Detail characterization of Mxene electrode structure is extremely important for understanding the fundamental mechanism of supercapacitor operation and for improving energy storage parameters.